This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The central objective of this project is to breed macaques that are specific pathogen free (SPF) and genetically characterized for MHC and full pedigree. These animals are made available as subjects to NIH supported investigators for AIDS related research and contribute to national health priorities. This objective is achieved at the Center by utilizing an existing colony of SPF macaques. This colony is expanded via breeding and recruitment of young animals from non-SPF breeding colonies for separation and viral screening. The colonies are virally maintained by routine blood collection for testing at specified intervals. This project provides trained personnel and resources that are necessary to maintain and expand the SPF breeding groups and manage them in order to optimize health and reproductive performance in support of national health related priorities. The YNPRC works closely with NCRR and the Coordinating Committee to implement recommendations regarding uniform husbandry procedures, standardization of screening tests and such other matters as the committee may deem necessary. To maximize the potential that national priorities for SPF production will be met, the YNPRC works in conjunction with other facilities, and investigators identified by NCRR, to maintain NCRR supported SPF colonies.